Wednesday, 9 May 2018

Screen Mirror Tips and Traps

One big difference between using a PC and a tablet or smartphone is the screen size. Even the largest tablet touchscreen is smaller than a laptop LCD. The comparison is even starker between smartphones and wide-screen PC monitors.
Using a smart device for extended periods would leave you with a nasty squint unless there was some way to make the screen bigger.

Fortunately, most devices should be able to 'cast' their screens wirelessly to TVs and monitors.

Method: MHL cable

MHL cables usually connect the micro-USB data/charging port of your device to the HDMI port of your TV.
Cutting to the chase, I do not recommend them. Support is poor across devices. This is supposedly due to the standard being proprietary.
Even though cables can charge at the same time, it doesn't offset the power drain on the device. And if you ever root or install a custom OS on your device, you may as well throw out the cable as it probably won't be supported.
Furthermore, few stores seem to stock MHL cables, so you are limited to ordering off the internet.

Method: Wireless screen casting

Wireless casting is known by many names including Airplay, Miracast, and Chromecast.
Many 'Smart' TVs support casting out of the box, so if you have one, you may be lucky and find that it works with your device.
Otherwise, you'll need to buy a 'dongle', that usually plugs into an HDMI port on your TV. I'm using a variant of the AnyCast M2, which supports most standards. At time of writing, they're around USD$40 in-store, or USD$10 online.


Buy in-store. Device support is not bad, but inconsistent, and returning a dodgy device to a store is a lot easier than mailing it back to an online merchant for a refund. Furthermore, store-bought dongles tend to have more legible instructions.

As with MHL cables, they work more reliably with devices that have unmodified firmware. Something to consider if you are thinking of installing custom firmware.
That said, I am typing this using LineageOS. That said, I needed to root the device and edit the build.prop file to add the following: persist.debug.wfd.enable=1
Pretty obscure, right? How to edit build.prop? First, thank goodness LineageOS can toggle root access (if you installed it), and fortunately, Root Explorer available on the Play Store has a specialised build.prop editing function. But if you have to ask, you're better off sticking with your stock ROM.


It is weird and cool to be able to edit documents from across the room (because the font size is so huge when casting from a phone). Not being tethered to the screen means there's no tactile reference frame. You have to constantly reestablish how what you do translates to what's on screen.

Background - Going Window-less

Despite my best efforts, my Windows laptop is dying. I haven't been without a PC since 1986, but instead of replacing it with another, I'm going to try and harness the underutilised computing power in my old smartphones and tablets to build something for work and play.


  1. Thinking of tablets, there is the iPad Pro, which comes with a pretty solid 13 inch display... however it’s arguably a laptop at this point. It certainly costs as much as one.

    I for one have been making do with nothing but an Android smartphone and a base model iPad (with a Bluetooth keyboard) for about a year. It’s basically a 10.5 inch laptop - iOS and Android are rapidly catching up.

    But I’m lucky. I’ve cracked 40, but my eyeballs are better than a lot of my twenty-something colleagues. So I can appreciate larger screens are required. I’m still happy to stare at teensy tiny screens... we’ll see how long that lasts.

    TVs though... I’ve always found their clarity, crispness, and colour to be awful. Maybe it’s because I buy $250 TVs and use them until they physically fail.

    Unfortunately, we haven’t reached the point where we can have a single device (like a phone), and have a big TV act as a window into it just yet. Rest assured that people are working on it (take a gander at Project Fuscia).

  2. There aren't any plans at this stage for Fuschia and the Flutter abstraction layer to be backwards compatible, so older device support will still be a matter of rolling the dice with custom OSs. I'll also attempt to fill the workstation gap with a Raspberry Pi, so watch this space.